Railway car truck conversion method



Aug. 11, 1959 R. B. coTTRl-:LL

` RAILWAY CAR` TRUCK CONVERSION METHOD 4 Sheets-Sheet l Filed Jun'e 17, 1955 4 INVENTOR; Z50/92! Me @i e585/ 4 BY @22M waxfg/ Aug. l1, 1959 R. B. coTTRELL RAILWAY CAR TRUCK -CONVERSIO METHOD 4 Sheets-Sheet 2 Filed June 17, 1955 INVENTOR. M5 e WMLW ' R. B. COTTRELL `2,898,870

CONVERSION METHOD Aug. 11, 1959 RAILWAY CAR TRUCK 4 Sheets-Sheet 3 Filed June 17, 1955 INVENTOR.

" R. B. COTTRELL RAILWAY CAR TRUCK CONVERSION METHOD Aug 11, 1959 4 Sheets-Sheet 4 Filed June -l'7, 1955 INVENToR. Me

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Robert B. Cottrell, Deerfield, Ill., assiguor to American Steel Foundries, Chicago, Ill.,y a corporation of New Jersey Application .time 11, 19ss,vserial No. 516,238. 14 charlatanes-'197) This invention relates to railway car trucks and particularly to conventional freight car trucks wherein a bolster member is resiliently supported by springs carried on spring seats of the truck side frames.

Since the advent of a new improved type-of 'snubbed truck, considerable thought has been given tothe possibility of economically converting existing freightl car trucks to the new improved type.

The majority of existing trucks were the so-called double truss, self-aligning, spring plankless type. This type of truck comprised a bolster resiliently mounted in an opening of a' side frame and wherein arcuate surfaces on the sides of the bolster ends maintained contact with corresponding arcuate'Y surfaces ou the columns ofthe side frames. The new snubbed truck resembles the double truss, 'self-aligning, spring plankless type truck, except that it includesaspring-'loaded snubbing element which is urged into frictional engagement with friction vsurfaces on the columns of the side frames.r4 This type of truck has a number of advantages. First of all, in the new snubbed truck there is obtained a uniform snubbing action between the bolster and the side frame through the entire range of the direct spring travel in either upward and downward direction. This uniform snubbing action allows the springs to provide the maximum cushioning effect inherent in the particular springs. Furthermore, the snubbed type of construction permits the use of long travel springs with consequent vbetter riding qualities, fewer hot boxes and lower maintenance cost. The design also provides controlled snubbing of any lateral movement of the bolster in the truck side frame openings.

A method has` finally been devised to :accomplish the conversion of a double truss, self-aligning, spring plankless type truck to the improved snubbed truck in a simple and economical manner and which -will give complete satisfactory performance. Obviously the general method would also be applicable to other conventional types of freight car trucks, either with or without spring planks, though for descriptive purposes only the planldess type has been considered.

This method is more clearly brought out in the following specification and drawings, wherein:

Figure 1 is a fragmentary perspective view of the double truss, self-aligning, spring plankless truck,

Figure 2 is a fragmentary side elevation of the converted truck structure,

Figure 3 is a plan view of the bolster end showing the manner in -which it is modified,

Figure 4 is a view taken at line 4-4 of Figure 3,

Figure 5 is an exploded isometric view of the various components of the modified bolster, and

Figure 6 is an isometric view of the converted truck but with portions of the side frame and bolster not shown.

Referring first to Figure l, which illustrates the double truss, self-aligning spring plankless truck, the side frame 2,398,873 VPatented Aug. ll, 1959 indicated generally at 10 is seen to comprise a tension member 12 and a compression member 14 and a pair ofqspaced columns 16. These members define a bolster opening 18. The side frame 10` is supported in the usual manner by the wheel and axle assemblies which are not shown in the drawings. 'Ille bottom portion of the bolster opening forms a spring seat 20 which carries `a plurality of compression springs 24 which in turn resiliently support the bolster indicated generally at 22. It should be noted that the inwardly facing surfaces of the columns 16 are arcuately concave as at 26. It should be noted also that the sides of the bolster ends are formed into convex arcuate surfaces 28 which are engageable with the surfaces 26.

Figure 2 illustrates a typical construction of the new improved snubbed truck. In this type of truck, the inwardly facing surfaces of the side frame columns 16 are provided with opposed substantially parallel plates 30 which present friction faces 32 for the snubbing elements 36 which are contained in the boloster. The bolster itself has been provided with a plurality of pocket-forming inserts indicated generally at 34. Frictional pressure is maintained -between each snubbing element 36 and the friction face 32 of the -adjacent side frame friction plate 30 by means of a pressure spring 38 in a manner which will be described hereinafter.

l Figures 3 and 4 show the manner in which the bolster ends must be modified to be adaptable to the conversion. Referring to these figures, it is seen that the bolster 22 is comprised basically of atop plate 40, a bottom plate 42, a pair `of side plates 44v interconnecting the top and bottom plates anda central web 46 interconnecting the top .and bottom plates and disposed approximately parallel to the side plates. The first modification of the bolster consists of cutting the bottom plate along the lines 48 (Figure 3) and 4cutting the top and side plates along the lines 50 whereby portions of the corners of the bolster will ybe removed. The removed portions of the bolster are those shown by the phantom lines in Figures 3 and 4 and designated by the numeral 52. The bolster with the corner portions removed is clearly illustrated in Figure 5.

The next step in the conversion process is the Iformation of the inserts 34 and the welding of these inserts 34 at the cutaway portions of the bolster. The insert 34 comprises a top wall 54 which is generally U-shaped and forms thereby a corresponding opening 56. Depending from the top wall 54 are a pair of side Walls 58 having portions thereof extending rearwardly of the top wall 54. These rearwardly extending portions, indicated at 62, take the place of bolster gibs 29, seen in Figure l, and are disposed on opposite sides of the related columns 16 so as to surround the columns and restrict lateral motion of the bolster relative to the side frame in the same manner as do gibs 29 presented on the bolster before conversion. The side walls 58 are offset inwardly to provide a pair of angularly disposed wedge faces `60 of the insert 34. The snubbing element 36 is also provided with a substantially vertical friction face 74 which, at assembly, is engagea-ble with the friction face 32 of the related side frame friction plate 30. Element 36 is also provided with top plate 76 which forms a bearing surface for the spring 38. In assembly the spring 38 is preloaded a predetermined amount and is squeezed by the bottom plate 42 of the bolster and the top plate 76 of the `snubbing element. The snubbing element is, therefore, constantly urged against the wedge face 60 and outwardly against the friction face 32 of the plate 30 each.

The modification of the side frame is best illustrated in Figure 6. This modification consists of the formation of the friction plates 30 comprising a friction face 32, a

plurality of welding flanges 33 and a support bar 3S. The friction plates are welded (as shown in Figure 6) to the inwardly facing surfaces of the columns 16. Their purpose is to provide a flat friction surface 32 instead of the concave arcuate surface 26 which had existed prior to the modification.

The structure of Figure 6 represents the converted truck.

of the improved snubbed type, wherein a controlled frictional snubbing action is provided between the friction face 74 of the snubbing element and the friction face 32 of the friction plate 30. This snubbing action accommodates the soft cushioned long travel spring action which is preferred.

I claim: Y

1. The method of converting an existing railway car truck of the type having a side frame provided with a bolster opening defined in part by a column member and having an undamped bolster therein comprising a top, a bottom, and a pair of side walls to one in which the bolster is frctionally damped in its vertical movement within' said opening, said method comprising the steps of: cutting away a predetermined portion of the top wall disposed adjacent and inwardly of the column member, cutting away the entire side wall disposed adjacent and inwardly of the column member, cutting away a predetermined portion of the bottom wall disposed adjacent and inwardly of the column member, placing an insert within the cutaway top, bottom, and side walls and firmly securing said insert' to said bolster, and assembling a fric tion shoe spring and a friction shoe within said insert, and firmly securing to the column member a friction plate having a friction surface engageable with the friction surface of the shoe.

2. The method of converting an existing railway car truck of the type having a side frame provided with a bolster opening defined in part by a column member and having an undamped bolster therein comprising a top,

a bottom, and a pair of side walls to one in which the 4bolster is frictionally damped in its vertical movement within said opening, said method comprising the steps of: cutting away a predetermined portion of the top wall disposed adjacent and inwardly of the column member, cutting away the entire side wall disposed adjacent and inwardly of the column member, cutting away a predetermined portion of the bottom wall disposed adjacent and inwardly of the column member, placing an insert within the cutaway top, bottom, and side walls and firmly securing said insert to said bolster, and placing in the insert a friction device having a friction surface engageable with a friction surface presented by the column member.' v

3. The method as set forth in claim 2 in which the insert has a generally U-Shap'ed top wall adapted to -be welded to the bolster, spaced side walls depending from the top wall, and portions extending outwardly from the sidewalls on opposite sides of the column member to restrict lateral motion of the bolster relative to the side frame. i

4. The methodas set forth in claim 2 in which the insert has an inclined wedge surface complemental to and mating withan inclined wedge surface ofthe friction device,

Referencesy Cited in the file of this'patent UNITED STATES PATENTS 

